Power driven type action in electric typewriter

ABSTRACT

Power driven type action in electric typewriter comprising a power driven rotary toothed snatch roll continuously rotated during operation, a pivotally mounted actuating lever connected to driven members including a type bar, spring biased engage member provided to move on the actuating lever having a pawl engageable with a tooth of the snatch roll, and an intermediate lever provided on the actuating lever. Depression of a key lever causes the intermediate lever to rotate to engage the intermediate lever with the engage member. Thereby the engage member is rotated and the pawl thereof is engaged with a tooth of the snatch roll, so that the engage member, intermediate lever and actuating lever are rotated together by the snatch roll. Thus printing operation is performed.

United States Patent [191 @saka POWER DRIVEN TYPE ACTION IN ELECTRIC TYPEWRITER [75] Inventor: Takatoshi Osaka, Tokyo, Japan [73] Assignee: Citizen Watch Company Limited,

Shinjukuku, Tokyo, Japan [22] Filed: June 23, 1971 [21] Appl. No.: 155,884

[ l Foreign Application Priority Data July 2, 1970 Japan ..45/57863 [52] US. Cl. 197/17 [51] Int. Cl B4lj 23/08 [58] Field of Search 197/17, 183

[56] References Cited UNITED STATES PATENTS 2,905,296 9/1959 Stuiber et al. 197/17 3,342,295 9/1967 Hishida 197/17 3,623,587 11/1971 Link l 197/17 2,931,481 4/1960 Saltd 197/17 2,896,765 7/1959 Enders 197/17 2,901,079 8/1959 Barkdoll 197/17 3,021,936 2/1962 Lambert 197/17 3,638,775 2/1972 Hishida et al 197/17 June 112, 1973 Primary Examiner-Robert E. Pulfrey Assistant Examiner-R. T. Rader Attorney-Howson & Howson [57] ABSTRACT Power driven type action in electric typewriter comprising a power driven rotary toothed snatch roll continuously rotated during operation, a pivotally mounted actuating lever connected to driven members including a type bar, spring biased engage member provided to move on the actuating lever having a pawl engageable with a tooth of the snatch roll, and an intermediate lever provided on the actuating lever. Depression of a key lever causes the intermediate lever to rotate to engage the intermediate lever with the engage member. Thereby the engage member is rotated and the pawl thereof is engaged with a toothof the snatch roll, so that the engage member, intermediate lever and actuating lever are rotated together by the snatch roll. Thus printing operation is performed.

4 Claims, 2 Drawing Figures PAIENIEDJUNIZHH 3,738,470

SHEET 1 [1F 2 PATENTEB 2975 SHEET 2 [1F 2 POWER DRIVEN TYPE ACTION IN ELECTRIC TYPEWRITER The present invention relates to a power operated typewriter in which driven members such as type bars are driven by electric motor, and more particularly to a power driven type action in which an engaging means is provided on an actuating memberand is engageable with a tooth of the power driven rotary snatch roll.

In the conventional power operated typewriter having a power driven snatch roll, each engaging member of the type action engages with the snatch roll at various irregular positions on occasion. More particularly, the pawl of the engaging member occasionally engages with the bottom portion of the tooth of the snatch roll or with tip end portion thereof. Consequently, energy given to the driven members including type bar is inconstant, which results, for example, in irregular printing. This is a frequent problem in such a typewriter that the engaging means is directly actuated by the key lever to be engaged with the snatch roll, so that moving speed of the engaging member toward the snatch roll is varied according to depression speed of the type key. In addition, the conventional typewriter produces a noise when the engaging member engages with the snatch roll and gives a shock caused by the engagement to the operator.

In order to remove above described. disadvantages, an improved typewriter has been provided. In the improved typewriter, the spring biased engaging member is provided on the actuating member connected to the driven members including type bar, and held by a locking means out of engagement with the snatch roll. The engaging member is engaged with the snatch roll by releasing the locking means when the key lever is operated, and disengaged from the snatch roll by another mechanism after printing. In accordance with this typewriter, above described noise and shock is removed. However, the engaging member is rotated to be engaged with the snatch roll even in non-operating condition, if the type key is depressed. Accordingly, when the machine is driven, printing operation is actuated by engagement of the engaging member with the snatch roll, which results in misprinting. In addition, if two or more type keys have been depressed, the machine is not driven in a condition of engagement of engaging members with the snatch roll, because of heavy load. In order to dissolve these problems, the typewriter must be provided with a safety mechanism for preventing the depression of the key levers in non-operating condition or with a high power motor. As a result, the typewriter is complicated in construction and expensive.

Accordingly, main object of the present invention is to provide a power driven type action in which engaging member is engaged with the snatch roll in constant condition thereby clear and regularprinting being obtained.

Another object of the present invention is to provide a power driven type action which does not produce a noise and give a shock to operator, when the engaging member engages with the snatch roll.

Further object of the present invention is to provide a power driven type action which need not provide any safety mechanism or a powerful motor.

In the drawings:

FIG. 1 is a side view showing an embodiment of the present invention; and

FIG. 2 is an enlarged fragmentary view of FIG. 1.

Referring to the drawings, a toothed snatch roll 1 is fixed to a shaft 2, extends across the machine and is rotated in the counter-clockwise direction by a motor (not shown). 3 is a platen and 4 is a type bar. The type bar 4 is pivotally supported by a shaft 6 in the slit of a segment 5. The type bar 4 with types 7 is supported by a type bar rest 8 comprising shock absorbing material, and the type bar rest 8 is, in turn, connected to the segment 5 by some suitable connecting means. A sub-lever 9 is pivotally provided on a shaft 11 supported by a machine frame 10 and is also guided in combs formed in the machine frame 10 at arms 9a and 9b extending downward and upward, respectively. The type bar 4 and sub-lever 9 are pivotally connected each other by means of a link 12. An actuating lever 13 is pivotally supported on a shaft 15 secured in the machine frame 14 and having a slot 13a in the central part thereof, and a fan-shaped hole 13b in its lower part having a recessed portion with a shoulder 13c and a side wall 13d as shown in FIG. 2.

On the actuating lever 13 is provided an engage member 16 having a pawl 16d which comes into engagement with the snatch roll 1. The engage member 16 has a pin 17 slidably engaged with the slot 13a of the actuating lever 13. Between the engage member 16 and the actuating lever 13 is connected an engaging member actuating spring 18, so that the engage member 16 is biased clockwise and also downward against the recessed portion 13c of the actuating lever 13.

An intermediate lever 19 which acts to engage the engage member 16 with the snatch roll 1 is pivotally mounted to the actuating lever 13 by a pin 20. The intermediate lever 19 has a bent portion 19a engageable with a key lever 24 and a nose 19b to actuate the engage member 16. The intermediate lever 19 is biased clockwise by a return spring 21 to engage the bent por tion 19c thereof with the locating edge 13g of the actuating lever 13 and with the edge of the engage member 16, so that the engage member 16 is biased counter-clockwise against the force of the spring 18 and while the actuating lever 13 is biased clockwise to be yieldably held against a cushion stop pad 23 provided across the machine at the end portion 13f. The actuating lever 13 is pivotally connected to the sub lever 9 by a link 22.

The key lever 24 is rotatably mounted on a shaft 29 and guided by guide combs 30 and 31. The key lever 24 is urged upwardly by a leaf spring 34 secured to the machine frame 14 against noise reducing and shock cushioning pad 32 fixed to the member 31. The key lever 24 has a type key 33 for operating the machine.

The key lever 24 can be depressed to a normal position and further forcibly depressed to an abnormal position. A bail 35 'as stopper for each key lever 24 is pivotally mounted by the shaft 15 across the machine and biased counter-clockwise by a spring 36 against the pad 32. The bail 35 has a bent portion 35a on which secured a cushion pad 37. If the key lever 24 is depressed to the normal position where the projection 240 of the key lever abuts on the pad 37, nonrepeat typing is performed as hereinafter described. When the key lever 24 is further depressed after abutting on the pad 37 and held in the abnormal position in which the projection 24c abuts against the stopping portion 31a of the guide comb 31, repeat typing is operated. In order to prevent the repeat typing at the normal position even if the key lever 24 is held in the position, a repeat preventing lever 25 is rotatably provided on the key lever 24 by a pin 26 and urged counter-clockwise by a spring 28 to engage the pin 27 provided on the lever 25 with the hock end 24a of the key lever 24.

In operation, when the type key 33 is depressed to the position 33 as shown in FIG. 1, the key lever 24 is rotated clockwise about the shaft 29, so that the end of the repeat preventing lever 25 engages with the bent portion 19a of the intermediate lever 19 to rotate the lever 19 counter-clockwise. Thereby the nose 19b of the lever 19 engages with the bent portion 16b of the engage member 16 to move the member upwardly along the slot 13a and shoulder l3e of the fan-shaped hole 13b, and the bent portion 190 removes from the edge 16c. By the upward movement of the engage,

member 16, the bent portion 160 is removed from the shoulder 13e, so that the member is rotated clockwise by the spring 18 about the shaft 17 to the position 16a where the bent portion 16a abuts on the edge 13d. At this time, the pawl 16a is positioned at 16d and engages with a tooth of the continuously rotated snatch roll 1, so that the engage member 16 is moved downwardly by the snatch roll. Since the pin 17 engages with the slot 13a and the bent portion 16a engages with the hole 13b, the engage member 16 and the actuating lever 13 are rotated together counter-clockwise about the shaft against the force of the return spring 21. Since the engage member 16 is rotated by the spring 18 as above described, the rotating speed of the member 16 is determined in a fixed value by the resilient force of the spring 18 without connection with the depression speed of the type key 33.

Counter-clockwise rotation of the actuating lever 13 causes the sub-lever 9 to rotate clockwise about the shaft 11 through the link 22, which in turn rotates the type bar 4 counter-clockwise about the shaft 6 through the link 12, thus printing is performed. The printing action is completed by momentum of each member after disengagement of the pawl 16d from the snatch roll 1. After printing, all of the members are returned to the home position by the return spring 21.

Now operation of the engage member 16 is more fully set forth hereinafter. When the left end of lever reaches to the position 25 in FIG. 2, the pawl 16d reaches to the position 16d, so that the engage member 16, actuating lever 13 and intermediate lever 19 are rotated together, and the bent portion 19a of the intermediate lever 19 removes from the left end of the lever 25. The bent portion 19a moves along the circle centering the shaft 15 and the left side edge of the left end of the lever 25 is formed in similar shape to the circle. Therefore, the movement of the bent portion 19a does not exert any resistant force on the key lever 24. Thus operator does not feel any shock from the type key.

When the bent portion 19a is removed from the lever 25, the intermediate lever 19 is permitted to rotate clockwise by the return spring 21. However, the intermediate lever ]9 does not rotate, because it is arrested by the engagement of the bent portion 19c with the edge 160 of the member 16 which is forced to rotate clockwise by engagement of the pawl 16d with the snatch roll 1. Thus the lever 19 is rotated together with the actuating lever 13 and engage member 16 about the shaft 15.

When the pawl 16d disengages from the snatch roll 1, the engage member 16 is rotated counter-clockwise about the pin 17 through the intermediate lever 19 by the return spring 21, so that the bent portion 16a moves to the right above the recessed portion of the hole 13b and the bent portion abuts on the edge 13g of the actuating lever 13, after which the engage member 16 moves downwardly by the spring 18 so that the bent portion 16a is engaged with the shoulder 132. Under this condition, the pawl 16d is held out of engagement with a tooth of the snatch roll 1, thus the pawl does not engage with the tooth when each member returns to the home position by the return spring 21.

Even if the key lever 24 is held in the normal depressed position, each member returns to the initial position. More specifically, during the actuating lever 13 moving to the initial position, the bent portion 19a of the intermediate lever 19 engages with the underside of the lever 25 to rotate it in the clockwise direction against the resilient force of the spring 28. Accordingly the actuating lever 13, engage member 16 and intermediate lever 19 return-to the initial position shown in the drawings. Therefore, repeat typing is not actuated unless the key lever 24 is returned to the home position and depressed again.

The operation of repeat action now will be described. When the key lever 24 is depressed to the stopper 31a of the abnormal position together with the bail 35 against the force of the spring 36 as shownin FIG. 1 by 24c, the cam portion 24a formed at the end of the key lever 24 is located at 24a. Accordingly, during the actuating lever 13 returning after printing, the bent portion 19a of the intermediate lever 19 engages with the cam portion 24a so that the intermediate lever is rotated counter-clockwise. Thereby the engage member 16 is slided upwardly and rotated clockwise and the pawl 16d engages with the snatch roll 1. Therefore, if the key lever 24 is forcibly depressed and held in the abnormal position, typing operation is repeatedly actuated.

From the foregoing it will be understood that, in the typewriter in accordance with this invention, since the pawl 16d of the engaged member 16 is rapidly engages with a tooth of the driving snatch roll 1 at the constant velocity without connection with depression speed of the key lever when the key lever is depressed to a predetermined position, engagement condition between the pawl and the tooth is constant and thereby clear and regular printing is obtained. Because of rapid engagement of the pawl with the snatch roll, the machine does not produce harsh noise and does not give a shock to operator.

In addition, even if the key lever is depressed in nonoperating condition, the pawl 16d is held out of engagement with the snatch roll when the key lever returned, Therefore the type action does not operate when the snatch roll is driven, thereby any safety means for preventing the depression of the key lever need be provided.

I claim:

1. Power-driven type action in an electric typewriter comprising a power-driven rotary toothed snatch roll, an actuating lever pivotally mounted on a shaft and pivotally connected to driven members including a type bar, a spring biased engage member slidably and pivotally mounted on the actuating lever and having a pawl for pivotal displacement into engagement with the snatch roll, an intermediate lever pivotted on the actuating lever, return spring bias means tending to hold the intermediate lever and the actuating lever in the home position, and a key lever engageable with the intermediate lever, said engage member being locked at the position in which the pawl of the engage member is out of engagement with the snatch roll, and the intermediate lever having three projections one of which is engageable with the key lever and the second and third of which are engageable with the engage member to afford displacement of it relative to the actuating lever, the second projection being operable to slide the engage member and the third being operable to pivot the engage member to return it to said locked position, said intermediate lever being adapted to be rotated by the key lever to displace the engage member so that the pawl of the engage member engages with a tooth of the snatch roll, whereby upon rotation of the snatch roll, the engage member, the intermediate lever and the actuating lever are rotated together by the snatch roll to actuate type bar.

2. Power-driven type action in an electric typewriter in accordance with claim 1 wherein the actuating lever has a shoulder and an edge, and the engage member is provided with a portion adapted to pivot between the shoulder and the edge of the actuating lever upon sliding movement of the engage member to unlock said portion from said shoulder, said pivotal movement en gaging said pawl with the snatch roll.

3. Power-driven type action in an electric typewriter in accordance with claim 1 wherein the key lever has a cam portion engageable with the first projection of the intermediate lever during return movement thereof when the key lever is forcibly depressed further than normal depressed position, so that the intermediate lever is rotated again to displace the engage member to engage the pawl of the engage member with a tooth of the snatch roll.

4. Power-driven type action in an electric typewriter comprising a power-driven rotary toothed snatch roll, an actuating lever pivotally mounted on a shaft and pivotally connected to driven members including a type bar, a spring biased engage member slidably and pivotally mounted on the actuating lever and having a pawl for pivotal displacement into engagement with the snatch roll, an intermediate lever pivoted on the actuating lever, return spring bias means tending to hold the intermediate lever and the actuating lever in the home position, a key lever engageable with the intermediate lever, and a spring-urged repeat-preventing lever rotatably mounted on the key lever, said engage member being adapted to be locked at the position in which the pawl of the engage member is out of engagement with the snatch roll, the intermediate lever having three projections one of which engageable with the repeatpreventing lever and the second and third of which are engageable with the engage member to displace it slidably and pivotally respectively relative to said actuating lever, said intermediate lever being adapted to be rotated by engagement with repeat-preventing lever to slide and release the engage member from its locked position, so that the pawl of the engage member engages with a tooth of the snatch roll whereby upon rotation of the snatch roll the engage member, the intermediate lever and the actuating lever are rotated together by the snatch roll to actuate the type bar, and the intermediate lever can be returned to the initial position by rotating the repeat-preventing lever on the key lever by the first projection as it is returned by said return spring bias means. 

1. Power-driven type action in an electric typewriter comprising a power-driven rotary toothed snatch roll, an actuating lever pivotally mounted on a shaft and pivotally connected to driven members including a type bar, a spring biased engage member slidably and pivotally mounted on the actuating lever and having a pawl for pivotal displacement into engagement with the snatch roll, an intermediate lever pivotted on the actuating lever, return spring bias means tending to hold the intermediate lever and the actuating lever in the home position, and a key lever engageable with the intermediate lever, said engage member being locked at the position in which the pawl of the engage member is out of engagement with the snatch roll, and the intermediate lever having three projections one of which is engageable with the key lever and the second and third of which are engageable with the engage mEmber to afford displacement of it relative to the actuating lever, the second projection being operable to slide the engage member and the third being operable to pivot the engage member to return it to said locked position, said intermediate lever being adapted to be rotated by the key lever to displace the engage member so that the pawl of the engage member engages with a tooth of the snatch roll, whereby upon rotation of the snatch roll, the engage member, the intermediate lever and the actuating lever are rotated together by the snatch roll to actuate type bar.
 2. Power-driven type action in an electric typewriter in accordance with claim 1 wherein the actuating lever has a shoulder and an edge, and the engage member is provided with a portion adapted to pivot between the shoulder and the edge of the actuating lever upon sliding movement of the engage member to unlock said portion from said shoulder, said pivotal movement engaging said pawl with the snatch roll.
 3. Power-driven type action in an electric typewriter in accordance with claim 1 wherein the key lever has a cam portion engageable with the first projection of the intermediate lever during return movement thereof when the key lever is forcibly depressed further than normal depressed position, so that the intermediate lever is rotated again to displace the engage member to engage the pawl of the engage member with a tooth of the snatch roll.
 4. Power-driven type action in an electric typewriter comprising a power-driven rotary toothed snatch roll, an actuating lever pivotally mounted on a shaft and pivotally connected to driven members including a type bar, a spring biased engage member slidably and pivotally mounted on the actuating lever and having a pawl for pivotal displacement into engagement with the snatch roll, an intermediate lever pivoted on the actuating lever, return spring bias means tending to hold the intermediate lever and the actuating lever in the home position, a key lever engageable with the intermediate lever, and a spring-urged repeat-preventing lever rotatably mounted on the key lever, said engage member being adapted to be locked at the position in which the pawl of the engage member is out of engagement with the snatch roll, the intermediate lever having three projections one of which engageable with the repeat-preventing lever and the second and third of which are engageable with the engage member to displace it slidably and pivotally respectively relative to said actuating lever, said intermediate lever being adapted to be rotated by engagement with repeat-preventing lever to slide and release the engage member from its locked position, so that the pawl of the engage member engages with a tooth of the snatch roll whereby upon rotation of the snatch roll the engage member, the intermediate lever and the actuating lever are rotated together by the snatch roll to actuate the type bar, and the intermediate lever can be returned to the initial position by rotating the repeat-preventing lever on the key lever by the first projection as it is returned by said return spring bias means. 